Fungi and the ecological cascade to woodland

Let's say I'm converting a field site, dominated by grasses and forbs, over to a forest garden.

It's not just a case of planting trees. I've planted a lot of trees.

Here's what I've worked out on the basis of ecological principles.

The trees, in concert with the fungi, at some point trigger a cascade in the ecosystem, where the biota changes from one with a soil dominated by bacteria and the invertebrate life associated with that to one dominated by fungi, and the invertebrate life that fungi support. Woodland soils, for those who don't know, tend to be much more dominated by fungi than grassland soils.

So, how do I encourage and accelerate that cascade?

* I can introduce suitable fungi, especially mycorrhizas (and we looked at that on another thread: https://permies.com/t/55302/fungi/Edible-Mycorrhizas).
* Mulch to kill off the grasses and grassland forbs.
* I can add suitable compost teas.
* I can add soil and duff from similar habitats, which should contain at least some of the relevant microbiota, but at risk of introducing pathogens before organisms to compete with them are properly established.
* I can encourage lichens in the habitat. https://permies.com/t/55379/fungi/Loving-lichens

What else? Obviously, any attempt to move too fast and any anything I introduce will be outcompeted by the grassland biota, but there may be other things I haven't thought of.

Depending on size I would go for usual mulch as in ground up tree material. From my experience it is not sufficient to skip the newspaper/cardboard.

This will kill the grass and together with planting trees till help to out compete the old ecology.

For Ideal measures I would go for the following, that I never tested out of lack of time and stuff:

plow with pigs

plow with chickens

lay down inoculated cardboard

mulch with woody stuff

mulch with leafs

plant top story trees

plant under story trees

plant bushes to fill space while trees are small

plant forest edge species on the borders

don't forget to plant bulbs

I figure the mulch is key as it feeds the woodland microbes and changes the soil to more acidic like a woodland.

In my opinion compost tea is more bacterial and will not help with the switch.

You can spray any extra aggressive grass with vinegar water (50/50 mix) to kill off the super hardy types. This may also work in your favor bringing the soil ph closer to the slightly acidic I find most forests are.

I think that if your area is naturally wanting to be a forest, it will happen on it's own. HOwever, like most people, I wanted a particular type of forest. Food forest. The nice thing is if you do this gradually as you say, you will have more wood and tough stems to put into the soil, which will naturally move it into a forest. This is called succession. I chose dwarf and semi-dwarf trees, as I can access the fruit and more sun gets to the ground to help grow vegetables and edible weeds. Free wood chips from utility and tree companies help turn the soil toward fungal. Our lawn and pesticide/synth fertilizer and tilling moves it toward bacterial.
John S
PDX OR

I want to make a distinction between succession and cascade. In terms of cascade I'm talking about the changes in microbiota, for example, that happen as a result of the growth of trees and fungi.

Succession is a related (dependent) process, but not the same thing.

Ploughing with livestock strikes me as the last thing you want to be doing: they will rip up useful seedlings as readily as anything you don't want. Pigs, in particular, will knock over tree guards.

Neil Layton wrote:
Ploughing with livestock strikes me as the last thing you want to be doing: they will rip up useful seedlings as readily as anything you don't want. Pigs, in particular, will knock over tree guards.

That is why it is not the last but the first thing you want to be doing. Get rid of the plants and some of the seeds that belonged to the bacterial based ecology to make room to fill with the woodland species.

Dominik Riva wrote:

Neil Layton wrote:
Ploughing with livestock strikes me as the last thing you want to be doing: they will rip up useful seedlings as readily as anything you don't want. Pigs, in particular, will knock over tree guards.

That is why it is not the last but the first thing you want to be doing. Get rid of the plants and some of the seeds that belonged to the bacterial based ecology to make room to fill with the woodland species.

From an ecological perspective, that still makes no sense to me.

Nature does sometimes start from bare ground like that, but I'm struggling to think of examples of where she starts with bare ground and jumps straight to scrub, never mind woodland. She starts with forbs and grasses (typically in that order) and moves on from there.

Meanwhile, if it rains, you're going to lose a centimetre of topsoil. Free-range pig (whether true Sus scrofa or the domesticus ssp) keeping has been described as "open-cast soil mining" for a very good reason.

I'm interested in that transition point between forbs/grassland and woodland. Even when I've planted trees and then mulched I've mulched round the trees and shrubs: I haven't just covered the entire area. Every source I can think of emphasises some degree of habitat continuity between the old habitat and the new one.

It looks to me like another one of those cases where you have someone looking for a reason to keep livestock (like the sheep farmers here who want to describe keeping grassland trimmed to within a millimetre of its life "conservation" because it supports one bird species (i.e. skylarks (Alauda arvensis)) or the ranchers in North America with their domestic cattle (Bos taurus) on "improved" grassland they keep trying to pass off as prairie to the rest of us, knowing that most people are too ignorant of ecology to realise that domestic cattle and North American bison (Bison bison) are not ecological analogues).

No, this sounds like bad advice I have reason to reject. The same applies to chickens, for much the same reason.

I also don't see why it would encourage a fungal soil - the opposite, if anything.

I think "normal" succession would proceed without the disturbance of hogs, which are native in only a few areas of the world. In my region, armadillos root around a bit, but nothing like the feral non-native hogs, which plow up the ground in a dramatic manner. I think if we're trying to implement natural succession, we might try to emulate what naturally occurs, without introduced species such as hogs. My own locale is extremely erosive, and we try hard not to leave areas of bare soil if we can avoid them, because here it will erode to bare rock, with the flooding rains we get. In other parts of the world things might be different, the land might be more forgiving. But even there, if soil is plowed, by humans or by animals, there will be erosion and loss of humus, in my opinion. Where we do end up exposing soil here in my locale, as when we have a rainwater harvesting basin dug, we see the soil quickly covered by native forbs and some opportunistic "weeds" such as thistle. Eventually grass will grow, and then, possibly native shrubs, then trees. I expect the whole place will eventually be forest.

Tyler Ludens wrote:I think if we're trying to implement natural succession, we might try to emulate what naturally occurs, without introduced species such as hogs. My own locale is extremely erosive, and we try hard not to leave areas of bare soil if we can avoid them, because here it will erode to bare rock, with the flooding rains we get.

Here where I live some farmers till every year and there is bare exposed soil for a lot of winter months with out much visible erosion.
I know that this would never work in the tropics with it's torrential rains. For an even bigger contrast to your situation, I'm in the native wild boar range over here in central Europe.

If you plow with animals you need be on a scale where you can fence them in to a relatively small patch to be able to do the work fast and more or less complete.
Following that with covering with woody mulch and intense planting will shift the microbes fast with out loosing much soil in the process.
In my region I would even guess that I would end up with more soil if compared from just before and a year after the procedure.
My suspicion is that this could even work in your region if you do it in the dry season, water and shade the new plants and fungi to get them going fast enough to complete grow through and hold the soil and your addition of mulch before the wet season starts again.
If you have no months with out heavy rain then this seams totally inappropriate to advance forests in your region.

Neil Layton wrote:It looks to me like another one of those cases where you have someone looking for a reason to keep livestock

I don't need a reason to keep livestock. Sure I plan on getting some but even chicken are to big and destructive for my small property.
That is why I go with bees and later quail and rabbits.

It's just that I would have used them if I would have had access to them or maybe even got some if the scale of the operation would have made economical sense to get some.

What I personally did on my property is using woody mulch 10cm deep for the whole property. This resulted in me buying 25m³ ground up trees material from a landscaper/gardener.
I didn't had time and the money to do the newspaper or cardboard let alone inoculate it with fungi and as a result now I have a lot of dandelion pushing through the mulch. At least the grass is only visible at the edges where the mulch is not 10cm thick.
My trees and shrubs look happy with what I did so far.

From your comments I gather that you want to do big scale with minimal inputs and a minimal amount of disturbance.

Neil Layton wrote:Every source I can think of emphasises some degree of habitat continuity between the old habitat and the new one.

I'm curios about your sources. The method I proposed would result in a steady movement of the process from patch to patch on a bigger scale or of a one time event at a smaller scale.
I would really worry about habitat continuity when I would be doing it at a scale of a whole valley but not for turning some fields in to woodland.

Neil Layton wrote:I'm struggling to think of examples of where she starts with bare ground and jumps straight to scrub, never mind woodland.

I have seen ruderal community where grass played no role at all and it looked like it did go from rubble directly to shrub and later trees - granted this was without soil to start with or soil buried deep under the rubble.

Neil Layton wrote:No, this sounds like bad advice I have reason to reject. The same applies to chickens, for much the same reason.

I also don't see why it would encourage a fungal soil - the opposite, if anything.

From your first post:

Neil Layton wrote: What else? Obviously, any attempt to move too fast and any anything I introduce will be outcompeted by the grassland biota, but there may be other things I haven't thought of.

The shock I would apply with the animal tilling is only once and specifically intended to open a niche and close it as fast as possible by inoculating, mulching and planting.
This shock is what makes a faster move possible and dampens the ability of the grassland biota to out compete your introduced species.

Neil Layton wrote:I'm interested in that transition point between forbs/grassland and woodland.

I don't know how it looks in your region but here it looks like this:

Grass

Stinging nettle and bramble

Elder and blackthorn

trees

All this is overlapping and protected with thorns as otherwise the deer would eat all the young trees.
I don't know what happens in the ground with the fungi but to me it looks like it is more about shade and thorns then about soil microbes.

Dominik Riva wrote:

Here where I live some farmers till every year and there is bare exposed soil for a lot of winter months with out much visible erosion.

Many of our problems seem to be caused by European practices being used in places with conditions dramatically different from Europe. You might be able to practice plow agriculture for thousands of years in parts of Europe with no visible damage, whereas here in my locale there has been severe damage in only a couple hundred years of farming and ranching by European immigrants. People are proceeding with farming practices which seem to assume people won't be needing any food in the future, because there won't be any soil left to farm and ranch on if this keeps up, not to mention no climate suitable for agriculture.

Yes I know, the destruction looks horrible and is so stupid. What makes me really angry about this is that it looks like there are people doing this to the land and still make a profit and then move on like a locust plague.